In addition to pushing the Justice Department to investigate civil rights charges against Zimmerman, Sharpton told supporters he wants to see a rollback of stand-your-ground self-defense laws now in place in more than 20 states.

"We are trying to change laws so that this never, ever happens again," the Rev. Sharpton said.

Zimmerman shot when he was pinned down and getting his head bashed into concrete. Stand-your-ground has to do with retreating when you can. Even aside from the fact laws can't ensure that bad things never, ever happen again — or else why is there murder? — stand-your-ground made no difference in Zimmerman's situation.

Meanwhile, in Chicago, the reported number is 8,000, with Jesse Jackson as the big speaker, saying: "We must boycott Florida and stop 'stand your ground.'" Boycott Florida?

Rosaline Wilson, 62, said she came to the rally remembering her 14-year old brother who she said was killed by a police officer several decades ago while he was riding home from school. Because of the experience, she said, Wilson was not surprised by the Zimmerman verdict, but thinks there is hope for the future.